Slowbies still have the danger to them especially when they are the head shot only variety. You need to be accurate to take them down. The threat comes from having waves of them more than you can take on resulting in siege situations.

I really loved the book series. Good stuff, real nice. Can't wait for more of it, and this. And they aren't bite transmittable, just any recently deceased with a brain, like in Night of the Living Dead.

As I've said, though, I don't get why these things are so menacing. Find a road at the outskirts of the city and clear it, get a vehicle you can fire from (an APC is best but even a bulldozer or truck would work), then drive slowly along the road and make a lot of noise. Zombies will start following you, and it's a simple matter to have a few trained men with rifles picking off the Z's one by one (if Marine Snipers can pop the skulls of moving sailors in a bobbing lifeboat while on a bobbing ship through tiny windows, they can do this). It's a good idea to have a helicopter to provide extraction too, just in case things go badly.

This is something every military in the world could do en masse with ease. You'd clear the zombie menace in a matter of days, and for a bargain too.

"It all started one cold, december morning, when a biological experiment went wrong. Virus Z was quickly spreading... however due to modern, effieciant evacuation methods and an effective military response the reanimated dead were quickly killed off and like resumed as normal. The end."

One month before the zombie outbreak, an equally contagious disease spread through the masses. The disease had no obvious symptoms, and in fact, only altered a tiny fraction of the human brain. It removed the hosts ability to rationally protect themselves from zombie attacks.

No, they'd just have superior writing. If you can't make a threat credible, you change the threat to ensure that it is.

Left 4 Dead dealt with this nicely. The horde isn't a huge issue for those already immune and armed with weapons, but the super-zombies are dangerous, especially if you're alone. Plus, the virus is airborne, the zombies are fast, etc. The vast majority (90%) of the population was infected by this and turned early. Of the remaining 10%, nine percent are turned by scratches, bites, and bile, something anyone who has played the game can tell you is commonplace.

This is a credible threat. Within a matter of hours, a given city would be overrun, and, while a military response might be powerful enough to overcome it, there's no guarantee. Vast amounts of military personnel will likely have turned, there'll be chaos and disarray...

In short, L4D has a credible zombie apocalypse scenario. I prefer the slow-moving, headshot-only zombies myself, but I still love L4D and it shows that thought went into this.